POV-Ray : Newsgroups : povray.binaries.images : Untitled S.F. [W.I.P.] Server Time
2 Nov 2024 02:15:57 EDT (-0400)
  Untitled S.F. [W.I.P.] (Message 1 to 8 of 8)  
From: Anthony D  Baye
Subject: Untitled S.F. [W.I.P.]
Date: 20 May 2011 04:20:01
Message: <web.4dd623a47a330d5d9c4fb0ad0@news.povray.org>
Just started this last night (That would be Wednesday for me).  It seems to be
coming along nicely, but I'm having a few problems.

First, I like the starfield, but I'd like to have more color, possibly a nebula,
maybe a few close stars.

Second, the planet.  It's supposed to have an atmosphere, but I can't seem to
get it to work.  The scale is 12 units to 100 meters or 3:25 scale, which makes
the gate roughly 6km across.  I'm currently looking at the gate, which is in
orbit around the planet at a distance of 35,768km

in actual units, the planet has a radius of 63,780ft.

I'm considering going to a 1:100 scale.

Third, if you look closely at where the stars appear on the dark side of the
planet, it seems to be out of round, but I may be mistaken.

Other than that, I have some work to do on the textures, and I want to make the
gate look more complex. (I've never really been good at greebling)

Any comments or suggestions are welcome.

Regards,
A.D.B.


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From: Nekar Xenos
Subject: Re: Untitled S.F. [W.I.P.]
Date: 20 May 2011 07:42:40
Message: <op.vvr2tbi7ufxv4h@xena>
On Fri, 20 May 2011 10:17:40 +0200, Anthony D. Baye  
<Sha### [at] spamnomorehotmailcom> wrote:

> Just started this last night (That would be Wednesday for me).  It seems  
> to be
> coming along nicely, but I'm having a few problems.
>
> First, I like the starfield, but I'd like to have more color, possibly a  
> nebula,
> maybe a few close stars.
>
> Second, the planet.  It's supposed to have an atmosphere, but I can't  
> seem to
> get it to work.  The scale is 12 units to 100 meters or 3:25 scale,  
> which makes
> the gate roughly 6km across.  I'm currently looking at the gate, which  
> is in
> orbit around the planet at a distance of 35,768km
>
> in actual units, the planet has a radius of 63,780ft.
>
> I'm considering going to a 1:100 scale.
>
> Third, if you look closely at where the stars appear on the dark side of  
> the
> planet, it seems to be out of round, but I may be mistaken.
>
> Other than that, I have some work to do on the textures, and I want to  
> make the
> gate look more complex. (I've never really been good at greebling)
>
> Any comments or suggestions are welcome.
>
> Regards,
> A.D.B.


For the atmosphere and stars you could look at my code here:
http://news.povray.org/op.u61y64hyufxv4h@xena


-- 
-Nekar Xenos-


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From: Thomas de Groot
Subject: Re: Untitled S.F. [W.I.P.]
Date: 20 May 2011 07:58:53
Message: <4dd6577d$1@news.povray.org>
"Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> schreef in bericht 
news:web.4dd623a47a330d5d9c4fb0ad0@news.povray.org...
> Just started this last night (That would be Wednesday for me).  It seems 
> to be
> coming along nicely, but I'm having a few problems.
>
> First, I like the starfield, but I'd like to have more color, possibly a 
> nebula,
> maybe a few close stars.

There is the galaxy.inc macro by Chris Colefax, though I am not sure where 
it resides nowadays... I have a copy if you want.

>
> Second, the planet.  It's supposed to have an atmosphere, but I can't seem 
> to
> get it to work.  The scale is 12 units to 100 meters or 3:25 scale, which 
> makes
> the gate roughly 6km across.  I'm currently looking at the gate, which is 
> in
> orbit around the planet at a distance of 35,768km

The following code is by Tek and creates a nice atmosphere:
//start code
  //atmosphere by Tek
  difference {
    sphere { 0, 21.1 }
    sphere { 0, 20.0 }
    hollow
    pigment { rgbt 1 }
    interior {
      media {
        scattering {
          1, rgb <0.05, 0.17, 0.3>*1
          extinction 1
        }
        density {
          function {exp( -(sqrt(x*x+y*y+z*z)-20)/4 )}
          density_map {
            [0 rgb 0.0]
            [1 rgb 0.1]
          }
        }
      }
    }
  }
//end code

Thomas


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From: clipka
Subject: Re: Untitled S.F. [W.I.P.]
Date: 20 May 2011 09:05:57
Message: <4dd66735$1@news.povray.org>
Am 20.05.2011 10:17, schrieb Anthony D. Baye:

> Third, if you look closely at where the stars appear on the dark side of the
> planet, it seems to be out of round, but I may be mistaken.

It is out of center, so it most surely /is/ distorted.

Maybe you want to try an ultra_wide_angle camera (which despite its name 
can also be used for non-ultra wide angle shots); it has less distortion 
of spheres at the periphery.


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From: Anthony D  Baye
Subject: Re: Untitled S.F. [W.I.P.]
Date: 22 May 2011 03:35:00
Message: <web.4dd8bbc4db6f07059c4fb0ad0@news.povray.org>
First, thank-you all for your suggestions, they've been most helpful.  In fact,
I've used almost all of them in one way or another.

It's becoming obvious, however, that I'm going to need the big guns for this
project, as my last render took... 16 hours..?  My tiny little core duo tablet
just isn't up to the task of giving me timely results on test renders, even
without radiosity.

I adapted the method Thomas suggested, using the following settings:

media {
     intervals 10
     scattering {
          5, <0.05, 0.17, 0.3>*0.05
          extinction 1.0
          eccentricity -0.23
          }
     samples 50
     absorption rgb <0.95, 0.55, 0.3>*0.05
     density {
          function {exp( -(sqrt(x*x+y*y+z*z)-63870)/4 )}
          density_map {
               [0 rgb 0.0]
               [1 rgb 0.1]
               }
          }
     }

Radiosity (The good settings):

radiosity {
     pretrace_start 0.01
     pretrace_end   0.005
     count 600

     nearest_count 12
     error_bound 0.1
     recursion_limit 3
     low_error_factor 0.2
     gray_threshold 0.2
     minimum_reuse 0.015
     brightness 0.58

     adc_bailout 0.01/2
     }

I know that 1 interval is supposed to be sufficient, and it may have to do with
my scale, but with only 1 interval I get a ring-effect in the media radiating
outward from the point of greatest light intensity.

The absorption was added because the original media gave the planet a reddish
cast.

These settings seem to work fairly well, except that the atmosphere is a too
dense.

The big guns:

Asus M4A79T Deluxe motherboard
AMD 3.0Ghz Hexacore processor
8Gb ram
1 TB Western Digital Caviar Black HD
Radeon HD 5870 graphics card

Regards,
A.D.B.


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From: John VanSickle
Subject: Re: Untitled S.F. [W.I.P.]
Date: 22 May 2011 16:07:45
Message: <4dd96d11$1@news.povray.org>
On 5/20/2011 4:17 AM, Anthony D. Baye wrote:

> Any comments or suggestions are welcome.

Go metric.  The math is much simpler that way.

Regards,
John


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From: Thomas de Groot
Subject: Re: Untitled S.F. [W.I.P.]
Date: 23 May 2011 03:17:13
Message: <4dda09f9$1@news.povray.org>
"Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> schreef in bericht 
news:web.4dd8bbc4db6f07059c4fb0ad0@news.povray.org...
> I adapted the method Thomas suggested, using the following settings:
>
> media {
>     intervals 10
>     scattering {
>          5, <0.05, 0.17, 0.3>*0.05
>          extinction 1.0
>          eccentricity -0.23
>          }
>     samples 50
>     absorption rgb <0.95, 0.55, 0.3>*0.05
>     density {
>          function {exp( -(sqrt(x*x+y*y+z*z)-63870)/4 )}
>          density_map {
>               [0 rgb 0.0]
>               [1 rgb 0.1]
>               }
>          }
>     }
>
> Radiosity (The good settings):
>
> radiosity {
>     pretrace_start 0.01
>     pretrace_end   0.005
>     count 600
>
>     nearest_count 12
>     error_bound 0.1
>     recursion_limit 3
>     low_error_factor 0.2
>     gray_threshold 0.2
>     minimum_reuse 0.015
>     brightness 0.58
>
>     adc_bailout 0.01/2
>     }
>
> I know that 1 interval is supposed to be sufficient, and it may have to do 
> with
> my scale, but with only 1 interval I get a ring-effect in the media 
> radiating
> outward from the point of greatest light intensity.

As method 3 is the default, intervals should *always* remain 1. I think that 
you also should use scattering 1 instead of  5 which probably creates the 
ring effect.

>
> The absorption was added because the original media gave the planet a 
> reddish
> cast.

The reddish cast happens mainly at the terminator line, as it happens in RL 
too ;-)

>
> These settings seem to work fairly well, except that the atmosphere is a 
> too
> dense.

Decrease the scattering rgb even further. Try <0.05, 0.17, 0.3>*0.005 for 
start and go on from there.

In the radiosity block, imo you should keep recursion_limit=1

In my posts here, entitled Fun with PlanetGenesis, in January 2011, you can 
see the results of my settings. My render time (on a dual core) is also much 
lower than yours. A couple of hours at most.

Thomas


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From: Alain
Subject: Re: Untitled S.F. [W.I.P.]
Date: 23 May 2011 13:10:35
Message: <4dda950b$1@news.povray.org>

> First, thank-you all for your suggestions, they've been most helpful.  In fact,
> I've used almost all of them in one way or another.
>
> It's becoming obvious, however, that I'm going to need the big guns for this
> project, as my last render took... 16 hours..?  My tiny little core duo tablet
> just isn't up to the task of giving me timely results on test renders, even
> without radiosity.
>
> I adapted the method Thomas suggested, using the following settings:
>
> media {
>       intervals 10
>       scattering {
>            5,<0.05, 0.17, 0.3>*0.05
>            extinction 1.0
>            eccentricity -0.23
>            }
>       samples 50
>       absorption rgb<0.95, 0.55, 0.3>*0.05
>       density {
>            function {exp( -(sqrt(x*x+y*y+z*z)-63870)/4 )}
>            density_map {
>                 [0 rgb 0.0]
>                 [1 rgb 0.1]
>                 }
>            }
>       }
>
> Radiosity (The good settings):
>
> radiosity {
>       pretrace_start 0.01
>       pretrace_end   0.005
>       count 600
>
>       nearest_count 12
>       error_bound 0.1
>       recursion_limit 3
>       low_error_factor 0.2
>       gray_threshold 0.2
>       minimum_reuse 0.015
>       brightness 0.58
>
>       adc_bailout 0.01/2
>       }
>
> I know that 1 interval is supposed to be sufficient, and it may have to do with
> my scale, but with only 1 interval I get a ring-effect in the media radiating
> outward from the point of greatest light intensity.
>
> The absorption was added because the original media gave the planet a reddish
> cast.
>
> These settings seem to work fairly well, except that the atmosphere is a too
> dense.
>
> The big guns:
>
> Asus M4A79T Deluxe motherboard
> AMD 3.0Ghz Hexacore processor
> 8Gb ram
> 1 TB Western Digital Caviar Black HD
> Radeon HD 5870 graphics card
>
> Regards,
> A.D.B.
>
>

You must keep intervals at 1.
Instead, you should increase the samples count as needed.
In your case, samples 500 would be significantly faster than intervals 
10 samples 50

The media computation can easily be about 3 times, maybe more, faster 
that way. You can reasonably expect render times under 6 to 7 hours.

Using samples 300 may be enough.

The video card have NO effect at all.

As you scatter more in the blue than other colours, it's normal that 
there is a redish cast similar to what appens for real. Why do you think 
the sun turns bright red at dusk and sun set?
Why does the moon turns brick red durins a lunar eclipse?


Alain


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